CVE-2026-85077 Sanic: HTTP response header injection via missing CR/LF validation in Sanic HTTP/1.1 responses
Attackers can inject headers into Sanic HTTP responses via missing CR/LF validation, enabling session fixation or cache poisoning.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85077?
CVE-2026-85077 is a high-severity vulnerability in sanic-org sanic, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Sanic is an opensource python web server/framework. Prior to version 24.12.1, and in version 25.12.0, the HTTP/1.1 response pipeline in sanic/response/types.py serializes response header names and values without rejecting carriage-return or line-feed characters. Applications that place attacker-controlled data in response.headers, file(..., filename=...), or cookie path and domain attributes can therefore emit injected headers and may split responses. Depending on application and proxy behavior, this can enable session fixation through injected cookies, cache poisoning, or security-header corruption. This issue is fixed in versions 24.12.1 and 25.12.1.
Weakness: CWE-113
Which versions are affected by CVE-2026-85077?
How do I fix CVE-2026-85077?
No fix has been published for CVE-2026-85077 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-85077 being exploited?
There is no known exploitation of CVE-2026-85077 in the wild and no public exploit code.
Sources
Also known as GHSA-m64h-22vf-48wm.